Steam accumulator and nozzle therefor



y 1957v P. ARANT .STEAM ACCUMULATOR AND NOZZLE THEREFOR Filed Feb. 18,1952 V INVENTOR ParzyArmZ ATTORNEYS IIH l nitecl States Patent o2,800,196 STEAM ACCUMULATORAND NOZZLE THEREFOR Perry Arant; San Gabriel,Calif.,' tassignor to Clayton Manufacturing Company, El Monte, Calih, acorporation of California Application February 18, 1952, Serial No.272,059

8Claims. (Cl. 183-95) ances which normally occur in accumulators havinga 1 tangentially directed discharge nozzle.

Another objec't'of' the invention is to provide a nozzle constructionwhich will not deflect liquid into the path of the'va'por leaving theaccumulator.

Another objectof the invention is to provide a nozzle for an accumulatorwhich willfunction over a wide range of steam demand and over asubstantial pressure range to keep the moisture content in the steam ata minimum.

Still another object of the invention is toprovide a discharge nozzlefor an accumulator thatiwill maintain a substantially uniformseparationof liquid and vapor'when performingunder increased velocities of thefluid, due to decreased operatingpressure; at any given constantcapacity.

A further object of the invention is-to provide a nozzle for anaccumulator'which will produce a multi -direction discharge tosubstantially uniformly distribute that part of the heated'fi'uid whichdoes not flash into vapor as a liquid film on the inner surface of theaccumulator wall A still *further object of the-invention is to providea nozzlefor an accumulator that willnot disturb the liquid that hascollected in the lower 'endof the accumulator, and which will provide anupper strata of liquid that has a temperature substantially equal tothat *ofthe' fluid being discharged into the accumulator; to therebyavoid heat lossthrough condensation intheaccumulator. g

A more specific object of theinventionis to provide-a distributing platefor an accumulator nozzle constructed so that the fluid issuing from thenozzle -is caused' to new at high velocity in agenerally circular. andupwardly inclined direction, whereby to permitthe fluid inthe centralportion-of the accumulator to flash into substantially dry vapor, and tocause the unvaporizedrliquid to impinge against the inner surface ofth'eaccumulator by the action of-centrifugal force, and to flow downwardlyby gravity to collect inthe lower end-of the accumulator;

Other objects and features of the invention will be apparent from thefollowing description takenin conjunction with-the accompanyingdrawings, in which:

Fig. 1 is a vertical sectional view through an accumulator havingincorporated therein a fluid discharge nozzle embodying the principlesof the present invention;

Fig, 2 is' a horizontal sectional view taken on the line of 2-2 of Fig.1; v

Fig. 3 is an enlarged plan view'of' the fluid distributing plate of thenozzle; v

Patented July 23,. 1957 ice 7 2? Fig. 4 is a sectional-view taken onthe-line-44 of Fig. 3; and a n Fig; Sis a side elevational'view of thefluid distributing plate, andlparticularly illustrating the angularityof the peripheraledges of the vanes with respect to the substantiallyflat central portion of said plate.

Referring now more particularly to Fig. 1, the accumulator is generallyidentified by the numeral 1 andlcomprises a tankincluding a cylindricalside wall section 2 having a dome-shaped head 3 at its upper end; Theheadr3 contains aring 4 tack-welded thereto at 5 and received in theupper end of the side wall 2. The adjacent edges of the wall 2 and head3 are permanently connectedtogetherby a continuous weld 6 backed by thering 4.

A generally similar head 7 is secured to the lower end ofthe side wall 2by acontinuous weld 8 backed by a ring 9 within the accumulator andtack-welded to the head 7,as indicated at -10. A stand 11 is disposedbelow .the accumulator i1 and is'welded at12 to the exterior of the.head 7.

Heatedfluid atvapor forming temperatures and pressuresisintroducedinto-the accumulator 1 through a pipe 13 having one-end.thereof connected to an elbow 14, which,l-ii1 turn, is connectedby aconventional pipe nipple 15r,.|to;a threaded centrally located opening16 in the head7. I The vdischargenozzle assembly is generally identifiedby thev numeral 17 and comprises-an inlet tube 18 flared at itstlowerend as indicated at 19 and welded or other-wise suitably. secured at 20in vertical alignment with inlet opening 16. The upper end of the tube18 :has a shoulder 21, whichforms a scatter a centrally apertured disk22 that is circumfe-rentially welded, as indicated at 23, to the upperend of the tube-1 8. Thed-isk 212 is received in the lower end of acylindrical member 23 and is oir'cum fie renti ally welded at its-outerperiphery to .saidcylindrical member, as indicated at 241 The disk 2-2'and-cylindrical member 23' are disposed concentrically in theaccumulator tank and cooperate to form a cup member in which the-disk 22forms the bottom wall and thercylind-rical member 231mm sid'e, walli,The inside diameter of cylindrical member 23 is substantially greaterthan that of the upper end of the tube 18 so as to provide a relativelylarge expansionzone where'the heated tfluid from tube 18 may flash infovapor. In the present example; as will be clearly seen in Figs. 1 :and2, the inside diameter of cylindrical member. 23 is approximatelyjfourtimes-as great "as the inside diameter oftube 1-8; I p

A shoulder 25 is :for'rned-by an annular recess in the inner surface of'the side member 23 and 'a fluid' dis tributing'm'ember or plate 26 isdisposed between said shoulder and the disk 22.1 The distributing plate26 is circular in plan view, as best shown in Figs. 2 and 3 and isinitially formed as a flat disk having a plurality of radial slots 27extending inwardly from the outer periphery thereof for a distance equalto about onefourth the diameter of 'the plate. Any suitable numberofslots 27 of any suitable depthmay be provided intlie plate 26, but forillustrative purposes four such slots of the-length specified have beenshown herein. The portions of the plate between "adjacent slotsconstitute'a continuous seriesof vanes 28,"'which are bent or inclinedrelative to a flat central portion 29, so thati'one' radial edge of eachvane extend-s downwardly on an angle of about 22 (measured in a verticalplane) relative to the horizontal plane of the central portion 29"(seeFig. 4)", andthe' other radial. edge of each vane extends upwardly on anangle. of about 22" (measured in a vertical plane) relative to the "samehorizontal plane; The 'bending of the vanes causes the -slots -27toassume the configuration of generally triangular-shaped orifices;"with -=a-n apex of about 44 (measured in a vertical plane) at thecentral portion 29. The'outer peripheral edge of each vane 28 isdisposed at an angle of about 16 to a plane parallel with the plane ofthe central portion 29, as best shown in Fig. 5. This provides for a lowangle spiral travel of the fluid within the,cup., The peripheral edgeof,each vane 28 is preferably shaved or ground so that it is trulyvertical. Each vane has a lower corner 31 and an upper corner 32, andwhen the distributing plate 26 is positioned in the cup, the uppercorners 32 of theivanes28 engage the shoulder 25 and the lower corners32 engage the disk 22. The periphery of the vanes 28. have a snug fitwith'the vertical inner face of the member 23 sothat there is no fluidleakage at these regions. The distributing plate 26 is preferablysecured to the member 23,.prior to welding the disk 22 in place, by tackwelding each of the vanes 28 thereto at a point adjacent the lowercorner 31 as indicated at 33. Thereafter, the disk 22 is positioned inthe member 23 and welded at 24 to maintain the disk 22, cylindricalmember 23 and distribution plate 26in permanently assembled relation.The tube 18 may be welded to the disk 22 either before or after saiddisk has been mounted in the member 23.

A stand pipe or overflow pipe 34 is tack-welded for convenience inassembly to the tube 18 at a plurality of points, as indicated at 35.The upper end of the overflow pipe 34 is spaced from the disk 22 andislocated in the accumulator 1 at a height corresponding to the maximumdesired liquid level and above a normal liquid level indicated at L. Thelower end of the pipe 34 is bent outwardly as indicated at, 36 and iswelded at 37 in alignment with a threaded opening 38. One end of a pipenipple 39 is threaded into the opening 38 and its other end is connectedwith an elbow 40 having connection with a conventional steam trap 41 fortrapping excess liquid out of the accumulator should the liquid level inthe accumulator rise above the upper end of the overflow pipe 34. Avalve 42 is connected in the discharge line from the steam trap 41, inaccordance with conventional practice. i The lower head 7 may have anysuitable number of threaded openings formed therein for the convenientconnection of various pipes thereto. This arrangement avoids thenecessity of making numerous pipe connectings to the side wall 2. Thus,a threaded opening 43 has a pipe nipple 44 connected thereto, which, inturn, is connected with a manually operable blowdown valve 45 connectedwith a blowdown pipe 46, as is conventional practice. A pipe 47, throughwhich liquid may be withdrawn from the accumulator 1 for recirculationthrough a heating coil (not shown), extends through the head 7 into theaccumulator and is sealed by a conventional pipe gland (not shown). Afeed water pipe F extends through the side wall 2 to a point adjacentthe pipe 18 for introducing feed water at a level such that the upperstrata of hot water in the accumulator is not disturbed, and in this waycondensation losses which would otherwise resuit from adding relativelycool feed water to the accumulator are avoided. Similarly, the head 3may have any desired number of threaded openings formed therein, and onesuch threaded opening 48 is centrally located in said head and has oneend of a vapor or steam dis charge pipe 49 mounted therein. A safetyvalve 50, for example, a portion only of which is shown, may beconnected with another opening in the head 3. Any openings not used maybe closed by a plug 51.

A conventional water gauge glass 52, the upper end only of which isshown in Fig. 1, may be connected with the accumulator 1, together witha plurality of test cocks 53 adapted to be opened to determine the waterlevel in the accumulator, independently of the gauge glass. It will beunderstood, of course, that the accumulator 1 is covered with suitablelagging or heat insulating material (not shown) to prevent heat losses.

In the normal operation of the accumulator and discharge nozzle shown inFig. 1, fluid under suflicient temperature and pressure to flash intovapor upon reaching a zone of lower pressure is introduced through thepipe 13 and travels upwardly in the tube 18 and enters the lower zone ofthe relatively large cup below the distributing plate 26 where itexpands and is deflected horizontally outwardly by the baflle effect ofthe central portion 29 of the distributing plate 26. The fluid is thenangularly directed by the vanes 28, which cause the same to dischargethrough the V-shaped orifice between the vanes 28 and to travelhelically upwardly in a generally circular path within the cup member23. Most of the hot fluid flashes into substantially dry vapor uponexpansion and rises in the central portion of the accumulator directlyabove the discharge nozzle 17. The fluid travels at high velocity, andcentrifugal force causes the fluid which has not flashed in'to vapor totravel upwardly along the inner surface of the cup member 23 and todischarge outwardly over the rim of'the cup against the inner surface ofthe wall 2. The distance or clearance between the outer periphery of thecup member 23 and the inner surface of the wall 2 is preferably quitesmall in order to quickly dissipate the rotating force imparted to theliquid. For example, in an accumulator having an internal diameter ofabout eight inches, the outside cup diameter is about 6 /8 inches, sothat the clearance space is only about 4 of an inch. While thecentrifugal force and velocity are quite high, the operation is smoothand the liquid thrown against the inner surface of the wall 2 neverrises to a height where it is deflected inwardly by the head member 3and, therefore, cannot fall back into the central stream of relativelydry vapor discharging from the accumulator through the pipe 49.

The multiple vane arrangement 28 assures a substantially uniformcentrifugal pattern in which the unflashed liquid assumes a somewhatannular form as it flows over the rim of the cup member 23, wherefore, asubstantially uniform film of liquid flows down the inside wall of theaccumulator. Thus, the conventional steam vortex within the accumulatoris eliminated, and the liquid which flows down the side wall 2 has itsrotating force spent before it reaches the liquid already collected inthe lower end of the accumulator. Hence, the unflashed liquid does notproduce any turbulence in the collected liquid.

The accumulator and discharge nozzle disclosed herein may be made of anydimensions desired and constructed to meet various service requirements,as will be readily understood. However, the particular dimensionsreferred to hereinbefore by Way of illustrating an operative example,and not by way of limitation, concern an accumulator adapted to operateover a pressure range of 50 to 150 pounds per square inch gauge. Therelation of nozzle velocity to steam pressure is very close, andgenerally varies in accordance with the density of the steam. Forexample, the weight of steam at 150 pounds per square inch is more thandouble that of the weight of steam at 50 pounds per square inch.Discharge velocities determined from actual tests show that in a 50 H.P.steam generating unit operating at a constant full capacity, the nozzledischarge velocity at 150 pounds per square inch gauge was 94 feet persecond, while at a pressure of 65 pounds per square inch gauge it wasmore than doubled, or about 192 feet per second.

It will be appreciated that it is diflicult to maintain a substantiallyuniform moisture content in the steam issuing from the accumulator 1under varying steam pressures, for example, from about 50 to 150 poundsper square inch gauge. This difliculty is increased where the demand onthe steam generator varies over a substantial range of the capacity ofthe unit. It is not uncommon for a unit to be required to operate fromanywhere between 50 percent to percent of its rated capacity. Changes ineither the steam demand, or the operating pressure, create acorrsponding change in the velocity of the discharge nozzle. Moreover,and contrary tofthe. performance 'of certain previous nozzle de'sig nstheincreased discharge velocity of the nozzle disclosedherein does notcreate disturbances in the liquid in the sepa-rationasordinarilyoccurswith high velocities so that the uniform separation of moisture fromliquidwhen-operating at increased velocities creates no undesirable.oper'atingcharacteristics.

A steam .generating uniti s con sidered to be satisfactory, from thestandpoint of moisture content, if the maximum moistureconteiit' is notexcess of 1 percent at an operating pressure lS Q po u ndsper squareinch. However, actual tst s have shown that thepresent. nozzle willprovide steam at a pressure 9f 150p0unds .per square inch Withamciisturecontent as low. as-.5 percent. At a muclilowerpressnreand higher nozzledischarge velocity, the moisture centent is even less, Specifically,tests have shown'thatwith a pressure of 5Q pounds per square inch, themoisture content in the steam leaving the accumulator was as low" as .25percent, which is substantially dry steam. H l H The principal advantageof providing substantially dry steam is quite apparent, namely, -thatwith dry stean'i,.the total heat' content is greater than that of steamcontaining moisture. Heat losses are proportionate to the percentage ofmoisture contained within the steam. Other economies result from theproduction of dry steam, in that there is no moisture content to causeinterferences in the steam consuming equipment, and there are no unduefeedwater losses due to moisture carry-over. Also, less trapping out ofhot liquid from the accumulator itself is required by maintaining theliquid level in the accumulator below the upper end of the overflow pipe34.

It will be understood that various changes may be made in the details ofconstruction, size, and arrangement of the parts of the accumulator anddischarge nozzle disclosed herein, without departing from the principlesof the invention or the scope of the annexed claims.

I claim:

1. An accumulator, comprising: a generally cylindrical tank having ahead at each end thereof, one of said heads having an inlet for heatedfluid and the other of said heads having an outlet for vapor; a nozzlepipe disposed in said tank and having one end thereof communicating withsaid inlet; a fluid discharge nozzle at the opposite end of said nozzlepipe including an expansion zone for said fluid to facilitate theflashing of said fluid into vapor; and an overflow pipe in said tank forunvaporized fluid having its upper end disposed below said dischargenozzle with one end thereof at a predetermined height to provide adesired maximum liquid level in said tank and having its opposite endconnected with an outlet opening in sailclli one head for dischargingexcess liquid from said ta 2. An accumulator, comprising: a tank; a headmember at one end of said tank having an inlet opening for heated fluid;a tube for heated fluid in said tank having ts lower end connected withsaid head and communicating with said opening; a discharge nozzlemounted upon the opposite end of said tube and comprising a cupshapedmember of substantially larger diameter than said tube to facilitateflashing of said fluid into vapor and having a central inlet opening anda vaned fluid distributing member in said clip above said openingarranged to direct the flow of fluid circumferentially and angularlyupwardly within said cup; and an overflow tube in said tank forunvaporized fluid having its upper end located at a predetermined heightto provide a desired maximum liquid level in said tank and having itslower end secured to said head member and communicating with an outletopening in said head member.

3. An accumulator, comprising: a generally cylindrical tank having ahead at each end thereof, one of said heads having an inlet for heatedfluid located centrally thereof and the other of said heads havingan'outlet for vapor;

fluiddistributing 6 a iiozzle pipey disposed I substantiallyconcentrically 3 in said tank and; liavirig -one endthereof-communicating with"saidinlet; a" flniunisoharge nozzle at theopposite endofsaidnozz'le p'ip'e ineluding'ari expansion zonefor andhavinglits upper end disposed below; said discharge opposite endc-onhect'ed with an" outlet opening in said 42' In an' accu' "ulator; a'tubular member for heated dischargenozzle mounted upon one end of saidtiibulanniemb comprising a cup having a axrelatively small centraliii-let opening-communicate with' said tubular member, and .a er Adisposed horizontally within sai'd-- cup"incli1'diii "perforatecentralportion larger thaii said"inlet'openingsp-aced axially relativeto said inlet ope'nin'g a d including vanes slightly inclined from thehoriz o about saidcentral portion, whereby the-fliwbf high velocity isdirected utwardly- -by said centralportion and tangentially up- 5. Anaccumulator discharge nozzle, comprising: a tube for heated fluid; a cupmember having a cylindrical side wall and a substantially flat bottomwall with said bottom wall mounted upon one end of said discharge tubeand having a relatively small central opening compared to the diameterofsaid side wall communicating with said tube, whereby said cup servesas an expansion chamher for heated fluid; and baflle means in said cupincluding a flat central port-ion spaced from said opening and a seriesof radial vanes adjacent said bottom wall of said cup and spaced asubstantial distance below the rim of said cup, said vanes havingportions disposed above and below the plane of said flat central portionwith their outer margins inclined on a slight angle to the plane of saidbottom wall for directing fluid flow upwardly and in a circumferentialdirection within said cup for discharge laterally outwardly bycentrifugal force over the rim of said cup.

6. An accumulator nozzle, comprising: a cup having a side wall and aflat bottom wall having a relatively small fluid inlet opening, wherebysaid cup serves as an expansion chamber for heated fluid; and a circularvaned fluid distributing member in said cup, said fluid distributingmember being provided with a plurality of radial slots extendinginwardly from the outer edge thereof, the outer marginal portions ofsaid distributing member between said slots being in contact with saidside wall and bent on an angle of about 16 relative to the plane of saidbottom wall to provide a plurality of inclined vanes with the uppermostedge of each vane disposed .at a point about midway of the depth of saidcup, whereby the fluid is directed circumferentially within the cup on alow angle of spiral for discharge laterally over the rim of said cup.

7. An accumulator nozzle, comprising: a cup having a cylindrical sidewall, said side wall having a shoulder formed on the inner surfacethereof and spaced a substantial distance from the rim of said cup; abottom wall spaced from said shoulder and provided with 'a relativelysmall inlet opening, whereby said cup serves as an expansion chamber forheated fluid; and a vaned fluid distributing member in said cup betweensaid shoulder and bottom wall, said fluid distributing member beingsubstantially circular and provided with a plurality of uniformly spacedradial slots extending inwardly from the outer edge thereof, the outermarginal portions of said distributing member between said slotsengaging said side wall and being bent on an angle of about 16 relativeto the plane of said bottom wall to provide a plurality of inclinedvanes with the uppermost edge of each vane engaged with said shoulderand the lowermost edge of each 'vane engaged with said bottom wall.

8. An accumulator, comprising: a vertical tank having a side wall and ahead at each end thereof, one of said heads having 'an inlet for heatedfluid and 'the other of said heads having an outlet for vapor; avertical nozzle pipe disposed substantially centrally in saidcylindrical tank and having its lower end communicating with said inlet;a fluid discharge nozzle mounted upon the upper end of said nozzle pipeand comprising a generally cupshaped member having a cylindrical sidewall and a substantially flat bottom wall providedwith a central openingcommunicating with said pipe, said cup-shaped member being ofconsiderably greater diameter than said nozzle pipe and having itscylindrical side Wall in close proximity to but spaced from the innersurface of said tank; and baflle means at the bottom of said c-upcooperating therewith to provide an expansion zone for said fluid andarranged to directrthe fluid, introduced into said eu-p through saidcentral opening, in a generally upward, tangential direction in saidcup, whereby said fluid may readily flash into vapor directly above thebottom of said cup, the rim of said cup being sufficiently close to theinner surface of said tank so that any unvaporized fluid is thrownsolely by centrifugal force laterally outwardly 'over the rim of saidcup into contact with said side wall and thus prevented from beingcarried upwardly into the tank by the vaporized fluid.

References Cited in the file of this patent UNITED STATES PATENTS1,017,275 Walker Feb. 13, 1912 1,279,758 Putnam Sept. 24, 1918 1,534,833Binks Apr. 21, 1925 1,693,849 Lorranine Dec. 4, 1928 1,751,324- GreenMar. 18, 1930 1,806,543 Kamrath May 19, 1931 1,930,476 Hawley Oct. 17,1933 1,931,194 Hawley Oct. 17, 1933 1,934,674 Lichtenthaeler Nov. 7,1933 1,981,549 Hawley Nov. 20, 1934 2,250,226 Juelson Ju-ly22, 19412,299,332 Marshall Oct. 20, 1942 2,557,332 Wright June 19, 19512,565,902 Wright et a1. Aug. 28, 1951 2,648,397 Ravese et al Aug. 11,1953

